Safety-fuse.



PATENTED DEC. 12, 1905.

J. SAGHS..

SAFETY FUSE.

APPLICATION FILED DEO.11,1903

JOSEPH SACHS,

OF HARTFORD, CONNECTICUT, ASSIGNOR TO THE JOHNS- PRATT COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

Specification of Letters Patent.

SAFETY-FUSE.

Patented Dec. 12, 1905.

Application fil ed December 11, 1903. Serial No, 184,718.

To all whom, it may concern:

Be it known that I, JOSEPH SACHS, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented an Improvement in Safety-Fuses, of which the following is a specification.

Heretofore in the construction of safetyfuses, especially commercial fuse-cartridges,

difliculty has been experienced in making the necessary joint between the fuse-terminals and the end caps, due to the fact that the heat required to make these joints was likely to disconnect the joints between the fuse-strip and its respective terminal wires; and the object of my invention is to overcome this difficulty.

In carrying out my present invention I employ with a casing and fuse-strip end caps of peculiar construction and fuse-strip-terminal wires which are electrically and mechanically connected to the said end caps in such a manner that there is no liability of disrupting the joint between the fuse-strip and its terminal wires in making the joint between said fuse-strip-terminal wires and said end caps. I also prefer to employ a filling ma terial of a non-heat conductive and heat-dissipating nature in granulated form to prevent the tendency of the fuse-strip to hang in a molten state when about to be blown and to assist in the dissipation of the heat and the absorption of the gases after the fuse-strip has been blown.

In the drawings, Figures 1 and 2 are central longitudinal sections of my improved safety-fuse, taken axially at right angles to one another; and Fig. 3 an end elevation of the same. Fig. 4 is a longitudinal cross-section of a modification of my invention, and Fig. 5 is an end view thereof. Figs. 6 and 7 are an elevation and plan,respectively, and Figs. 8 and 9 are an elevation and plan of modifications in the manner of connecting the fuse-strip to the terminals thereof; and Figs. 10 and 11 are respectively an elevation and plan of a further modification of the manner in connecting the fuse-strip and its terminal wires.

co represents a casing, preferably tubular and of a fibrous insulating material and provided with end-cap terminals 5 b, the end faces of which are axially cupped or recessed, so as to each form an inwardly-projecting funnelshaped wall 0, providing a central recess in the face of each end cap.

(Z represents a strip of fusible metal as commonly employed in devices of this class, and as fuse-strip terminals I preferably employ wires of good conductivity, which are looped centrally and through which at this point the ends of the fuse-strip (Z are passed, returned upon themselves, and joined by soldering the parts together or otherwise. The free ends of the fusestrip-terminal wires extend through the central apertures of the cupped portions of the end caps and into the recesses therein. Into these recesses I then flow a metal or other material f, surrounding the ends of the fuse-terminal wires 0, filling the recesses and making both mechanical and electrical connection between the fuse-stripterminal wires and the end caps and closing the apertures. In this construction the joint between the end caps and the fuse-strip-torminal wires may be readily made with no liability of injury or disruption of the joint between the fuse-strip and its terminal wires.

As shown in Figs. 4 and 5, the ends of the fuse-strip (Z may be secured between plates 2 by riveting the parts together or otherwise, in which instance the terminals 7) of the fuse device are preferably cast metal and provided with slots into which the plates 2 are passed and secured by making a joint similar to that described in connection with Figs. 1, 2, and 3 or otherwise.

It will be understood that the fuse-strip terminals may be bars instead of looped wires, as shown in Figs. 1 and 2, and, as shown in Figs. 6 and '7, the fuse-terminal bars a may be provided with bifurcated ends, between which the ends of the fuse-strip (Z are electrically connected, or, as shown in Figs. 8 and 9, the ends of the terminal bars 6' may be flattened and provided with openings through which the ends of the fuse-strip (Z are passed and electrically connected, or, as shown in Figs. 10 and 11, the ends of the fuse-strip may be pivoted to the terminal bars 0. It will also be apparent that these connections may be made in other ways without departing from the spirit of my invention.

A filling material g, as shown in Figs. 1 and 2-such as chalk, plaster-of-paris, or soapstone in a granulated form-is preferably employed and surrounds the fuse-strip and its terminals and fills the casing. The filling material is in a granulated form, because as such I have found that it tends to prevent the fusestrip sagging or hanging down when about to be disrupted as well as to dissipate the heat and absorb the gases after the dissipation. I am aware that similar substances in a pulverized state have been used as filling materials, and while in this form they assist in the dissipation of the heat and absorption of the gases upon dissipation of the fuse-strip they do not in any wise prevent the sagging of the fuse-strip.

I claim as my invention 1. A safety-fuse, comprisinga tubular casing, caps fitting said casing and having apertured sunken ends that extend into said casing, a fuse-strip having returned ends and having terminals or ends composed of doubled Wires threaded through the returned ends of the fuse-strip and so connected therewith and also passing through the apertures of the end caps into the sunken parts, and a material filling the sunken ends and surrounding the fuse ends or terminals and securing the same to the end caps.

2. A safety-fuse, comprising a tubular casing, caps fitting said casing and having apertured sunken ends that extend into said casing, a fuse-strip having returned ends and having terminals or ends composed of doubled wires threaded through the returned ends of the fuse-strip and so connected therewith and also passing through the apertures of the end caps into the sunken parts, a material filling the sunken ends and surrounding the fuse ends or terminals and securing the same to the end caps, and a granulated filling material within the said casing and surrounding the fuse-strip and portions of the terminals.

3. A safety fuse, comprising a tubular open-ended easing, caps fitting said casing and having apertured sunken ends that extend into said casing, and the extreme diameter of which substantially agrees with the inner diameter of the casing, a fuse-strip, terminals or ends connected with the fuse-strip and passing through the apertures of the end caps into the sunken parts, and a material filling the sunken ends and surrounding the fuse ends or terminals and securing the same to the end caps.

4:. A safety fuse, comprising a tubular open-ended casing, caps fitting said casing and having apertured sunken ends that extend into said casing, and the extreme diameter of which substantially agrees with the inner diameter of the casing, a fuse-strip, terminals or ends connected with the fuse-strip and passing through the apertures of the end caps into the sunken parts, a material filling the sunken ends and surrounding the fuse ends or terminals and securing the same permanently in place, and a granular filling material within the said casing and surrounding the fuse-strip and portions of the terminals.

Signed by me this 25th day of November, 1903.

JOSEPH SACHS.

lVitnesses:

Geo. T. PINCKNEY, ARTHUR O. BERRELL. 

